A friend of mine made me these super nice countersinks with a knurled aluminum shaft. To turn them into useful tools for manual work i designed and printed some hefts for them. For fun i did one in TPU, the other in ABS. Both work fine, but the TPU heft is much smoother and it’s slight flexibility gives a nice grip. The print quality of the TPU one is seriously much better, it was printed on the DuoCube, while the white one shows the Z wobble that my old machine acquired a few months back. I have to address that at some point in time, but hey, the machine is about 7 years old now and still pretty good for that.
On the left printed @0.15mm Layer height with an 0.5mm nozzle on my DuoCore @210°C. On the right printed @0.2mm Layer height with an unknown nozzle @200°C on a friends i3. What is interesting are the differences in slicing, the left was sliced using S3D, the right one with Slic3r.
I was very positively surprised by the new GreenTec filament from Extrudr, that i ordered on a whim alongside a couple of kilos of my usual ABS.
Not only does it produce a nice matte finish, it prints without any hint of warp, the stability is excellent and it is a dream to postprocess with any kind of tool.
The only two drawbacks i found so far are that it sticks so strongly to the printplate (aluminum with 3Dlac @60°C) that damage to the part or printplate are a very real threat and the current price of €56 / Kg
I hope the price goes down over time, but even at the premium it might be worth it, especially considered that i don’t have to feel so bad about producing garbage prints since GreenTec decomposes neatly, different to PLA.
As it turned out, it was a lot earlier than expected that the silicone sleaves from this posting
Silicone Sleave for Merlin made the trouble worthwhile. Some peculiar behavior of Marlin lead to a thermal runaway for a couple of seconds at full power. The silicone, that is rated for 450°C deteriorated, but the extruder remains unharmed and even the hotend survived thanks to the new cooling.
For those interested, what happened was that while homing Z Marlin stopped working completely. Everything was frozen including menu and the PID for the hotend, which got stuck with the heater switched on. I haven’t found the reason for the behavior yet, but i’ll do the homing before the heating in the foreseeable future.
For testing purposes i bought a spool of the new Esun ePC polycarbonate from RepRapWorld. While not cheap it isn’t actually very expensive with €20 for 1/2 Kg. Given that the Merlin Hotend uses a PTFE inliner i was a bit sceptic if it would withstand the 255°C, but no problems turned up at all.
As can be seen in the images bridging does not seem to be optimal, there are even some holes in the top surfaces, something that did not happen with a simpler testprint before. Maybe a bit slower print speed (this one was done with 130 mm/s default in S3D) or maybe lower temperature will help. The stability is good, i destroyed an earlier print using a pair of pliers and i had to use quite a bit of force. Also noteable, the layer adherence was excellent, the part did not brake along layers at all.
Given the very good heat resitance (even better than ABS) i think i will find a lot of uses for machine parts, especially extruder parts since according to Esun the ePC material is not inflamable.
One thing to note, the ePC did not stick to glass when i used 3DLac, i had to print it with an ABS raft, easy enough with the DuoCube 🙂